added sizeof() as alias of count() for Smaller/SmallerOrEqual

src/Analyser/TypeSpecifier.php

@@ -326,6 +326,26 @@ public function specifyTypesInCondition(
 						$context->true() ? TypeSpecifierContext::createTruthy() : TypeSpecifierContext::createTruthy()->negate()
 					);
 				}
+
+				if (
+					!$context->null()
+					&& $exprNode instanceof FuncCall
+					&& count($exprNode->args) === 1
+					&& $exprNode->name instanceof Name
+					&& in_array(strtolower((string) $exprNode->name), ['count', 'sizeof'], true)
+					&& $constantType instanceof ConstantIntegerType
+				) {
+					if ($context->truthy() || $constantType->getValue() === 0) {
+						$newContext = $context;
+						if ($constantType->getValue() === 0) {
+							$newContext = $newContext->negate();
+						}
+						$argType = $scope->getType($exprNode->args[0]->value);
+						if ($argType->isArray()->yes()) {
+							return $this->create($exprNode->args[0]->value, new NonEmptyArrayType(), $newContext, false, $scope);
+						}
+					}
+				}
 			}
 
 			$leftType = $scope->getType($expr->left);
@@ -404,11 +424,11 @@ public function specifyTypesInCondition(
 				$expr->left instanceof FuncCall
 				&& count($expr->left->args) === 1
 				&& $expr->left->name instanceof Name
-				&& in_array(strtolower((string) $expr->left->name), ['count', 'strlen'], true)
+				&& in_array(strtolower((string) $expr->left->name), ['count', 'sizeof', 'strlen'], true)
 				&& (
 					!$expr->right instanceof FuncCall
 					|| !$expr->right->name instanceof Name
-					|| !in_array(strtolower((string) $expr->right->name), ['count', 'strlen'], true)
+					|| !in_array(strtolower((string) $expr->right->name), ['count', 'sizeof', 'strlen'], true)
 				)
 			) {
 				$inverseOperator = $expr instanceof Node\Expr\BinaryOp\Smaller
@@ -429,7 +449,7 @@ public function specifyTypesInCondition(
 				&& $expr->right instanceof FuncCall
 				&& count($expr->right->args) === 1
 				&& $expr->right->name instanceof Name
-				&& strtolower((string) $expr->right->name) === 'count'
+				&& in_array(strtolower((string) $expr->right->name), ['count', 'sizeof'], true)
 				&& (new IntegerType())->isSuperTypeOf($leftType)->yes()
 			) {
 				if (

tests/PHPStan/Analyser/NodeScopeResolverTest.php

@@ -483,6 +483,8 @@ public function dataFileAsserts(): iterable
 		yield from $this->gatherAssertTypes(__DIR__ . '/data/filter-var-returns-non-empty-string.php');
 
 		yield from $this->gatherAssertTypes(__DIR__ . '/data/bug-5529.php');
+
+		yield from $this->gatherAssertTypes(__DIR__ . '/data/sizeof.php');
 	}
 
 	/**

tests/PHPStan/Analyser/data/sizeof.php

@@ -0,0 +1,47 @@
+<?php
+
+namespace sizeof;
+
+use function PHPStan\Testing\assertType;
+
+
+class Sizeof
+{
+	/**
+	 * @param int[] $ints
+	 */
+	function doFoo1(array $ints): string
+	{
+		if (count($ints) <= 0) {
+			assertType('false', min($ints));
+			assertType('false', max($ints));
+		}
+	}
+
+	/**
+	 * @param int[] $ints
+	 */
+	function doFoo2(array $ints): string
+	{
+		if (sizeof($ints) <= 0) {
+			assertType('false', min($ints));
+			assertType('false', max($ints));
+		}
+	}
+
+	function doFoo3(array $arr): string
+	{
+		if (0 != count($arr)) {
+			assertType('array&nonEmpty', $arr);
+		}
+		return "";
+	}
+
+	function doFoo4(array $arr): string
+	{
+		if (0 != sizeof($arr)) {
+			assertType('array&nonEmpty', $arr);
+		}
+		return "";
+	}
+}